


Surface Heat

by yast-erotic (yastaghr)



Category: Undertale (Video Game)
Genre: M/M, Mating Cycles/In Heat, POV Sans, POV Second Person, Sans has a tail, Sub Sans, tail sans
Language: English
Status: Completed
Published: 2017-05-20
Updated: 2017-05-20
Packaged: 2018-10-30 19:28:08
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,055
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10883400
Author URL: https://archiveofourown.org/users/yastaghr/pseuds/yast-erotic





	Surface Heat

This morning had been fairly normal, all things considered. Got up, rolled out of bed, rooted around in the empty fridge for something to eat, that sort of thing. Yeah, you’d felt a bit achy, but without Papyrus home to take care of you, getting sick didn’t come as a surprise. He’d probably scold you over the phone tonight for letting it happen. That sounded like him.

 

It was odd how much just putting on clothes had bothered you, but you chalked that up to the laziness. If you could have stayed in bed all day, you would have. But you had work to do, so clothes it was.

 

Deliveries today had been surprisingly difficult. It wasn’t like anyone had messed with your route or anything - heck, there wasn’t even construction today! But for some reason you couldn’t keep track of where you’d been long enough to get to the next stop. You’d taken double the normal amount of time, but instead of being as pissed as you’d expected them to be, your boss just waved you away. The look on their face was...odd. You didn’t know how to place it.

 

For once you were glad it was taking so long to find extra jobs. You didn’t think you could function much longer - stars, this cold was really messing with you. You’d just get your fries from Grillby’s and head home. 

 

Once inside though, everything fell apart. The warmth made you woozy, so you sat down at the counter to wait it out. Red Bird hadn’t been in his usual seat, just some human who wouldn’t stop talking. Most of the usuals were busy nowadays, but right now you missed the times when you could come in in a funk and no one would bother you. Talking took too much brain power.

 

You were really starting to lose it now. Why else would you be seeing Doggo growling like that? He was easily the most laid back sentry there was! Apart from you, anyway. He didn’t get angry. Confused, yeah. Annoyed, certainly. Angry, never.

 

At least the human had finally stopped talking. You could have kissed whoever got them to leave. With tongue, even. You wondered how it would feel - would it be tingly? What would they taste like? Sweet? No, salty, and their tongue would tangle with yours and coat your mouth with their taste. You moaned at the thought.

 

Warmth lapped at your mandible, and you opened your mouth eagerly, begging for that taste. You could barely make out the figure in front of you, a hazy blur of black and white topped with bright, bright yellow flames. Grillby?

 

“.....-ear me…..came in li…..heat?”

 

The words faded in and out of hearing, and none of them made sense. Of course Grillbz was hot - he was a flame. You’d been ragging on him for years to get his glasses checked, but you didn’t think it was that bad.

 

The tight band of elastic slid over your hips and down your femurs. Every millimeter it moved made you dizzy. Wow, maybe clothes had been a bad idea after all, if taking them off felt like this. Why were you wearing them in the first place?

 

You jerked as the raspy tongue licked at your pelvis. Woah, that was intense. Had 2b’s chihuahua gotten into your apartment again? Last time they’d just been gnawing, but this felt pretty good.  

 

The tongue worked its way lower, soaking each vertebrae from sacrum down to the end of your tail. Wait, why was your tail out of its sleeve? Had you forgotten to tie it up this morning? Crap, the dogs would never let you hear the end of this. They’d be calling it ‘cute’ and ‘adorable’ and next thing you know they’d be giving you a collar and inviting you to weddings. 

 

You tried to hide it between your legs, but someone’s paw grabbed hold of it, and someone else was holding your arms. You struggled, but the tongue kept licking. There was no stopping it now.

 

More words washed over you, but they made even less sense than last time. Couldn’t they see that you were busy trying to deal with this tail thing? You felt way too sensitive. Every lick was making you shudder, and you were sure you were rattling like a babybones. That was just the embarrassing icing on the top of the overwhelming cake of today. You felt the tears roll down your skull and just...surrendered.

 

A few licks later the tongue stopped. You almost missed it, but then someone stuck your tail in their mouth and then you didn’t. Fuck that felt good. You whined as they sucked, your phalanges digging into someone’s hands. Flickering thumbs rubbed at your carpals, and stars if that didn’t feel good too. Everything was so good and tingly and warm and...and it was overwhelming, that’s what it was! Since when was the world allowed to feel like this?

 

One of the hands around your tail let go, and a few seconds later you felt it stroking your lumbar vertebrae. You needed a new adjective for how good this was feeling. It was tight and hot and it kinda hurt, a bundle of feeling in your SOUL that- actually, you weren’t sure if you wanted it bigger or just gone. Everything was too much, too much, too much!

 

The bundle burst, and SOUL gook exploded all over your ribcage. Something else just as sticky and wet slid down your femurs. You trembled, suddenly cold. Your hands were the only part of you that felt warm. You looked down at them. They were held firmly in familiar flames.

 

“gri...illby?”

 

“.....Here.”

 

His oval glasses swooped into view waaay too close to your face. You tried to jerk back, but the hand - no,  _ paw  _ \- around your spine held you still.

 

“grillbz wha- what’s happening?”

 

He sighed. The warm air ghosted over your collarbone. It felt nice, relaxing.

 

The pop of your tail pulling out of someone’s mouth felt less so. It felt soggy and gross, and even having it moving at all felt weird.

 

Doggo panted out a laugh, “Don’t you know your heat cycle when it hits you, buddy?”

 

“my what cycle?”

 

Doggo stopped panting. Grillby’s flames popped loudly, and you flinched.

 

“Shit.”

 

“.....Language.”

  
  



End file.
